Add export/import facilities to the hive system

Details

Description

This is an enhancement request to add export/import features to hive.

With this language extension, the user can export the data of the table - which may be located in different hdfs locations in case of a partitioned table - as well as the metadata of the table into a specified output location. This output location can then be moved over to another different hadoop/hive instance and imported there.

This should work independent of the source and target metastore dbms used; for instance, between derby and mysql.

For partitioned tables, the ability to export/import a subset of the partition must be supported.